Cytogenomic Abnormalities in 19 Cases of Salivary Gland Tumors of Parotid Gland Origin

Salivary gland tumors (SGTs) of parotid origin are a group of diverse neoplasms which are difficult to classify due to their rarity and similar morphologic patterns. Chromosome analysis can detect clonal abnormalities, and array comparative genomic hybridization (aCGH) analysis can define copy number alterations (CNAs) from tumor specimens. Of the 19 cases of various types of SGTs submitted for cytogenomic analyses, an abnormal clone was detected in nine cases (47%), and CNAs were detected in 14 cases (74%). Recurrent rearrangements involving the PLAG1 gene at 8q12, recurrent CNAs including deletions of 6q, 9p (CDKN2A), and 17p (TP53), loss of Y chromosome, and gain of chromosome 7 were defined from these cases. Combined karyotyping and aCGH analyses could improve diagnostic yield. Future study for more precisive correlation of SGT classification with cytogenomic abnormalities will facilitate better diagnosis and treatment.

Thrombocytapheresis in Patient with Essential Thrombocythemia: A Case Report

Essential thrombocythemia (ET) is one of the myeloproliferative neoplasms, characterized by persistent thrombocytosis, platelets >450,000/μL, and evident clonal abnormalities like JAK2 V617F, MPL, CALR mutation and not fulfilling WHO criteria for MDS, CML, PV, and IDA. Here we report a 24-year-old female who presented with headache and was found to have thrombocytosis with a platelet count of 2,141 × 103/μL, diagnosed as ET as per WHO criteria 2008; she required ICU admission and thrombocytapheresis with a favorable outcome.

Bone Marrow Morphology Associated With GermlineRUNX1Mutations in Patients With Familial Platelet Disorder With Associated Myeloid Malignancy

Germline mutations in RUNX1 result in autosomal dominant familial platelet disorder with associated myeloid malignancy (FPDMM). To characterize the hematopathologic features associated with a germline RUNX1 mutation, we reviewed a total of 42 bone marrow aspirates from 14 FPDMM patients, including 24 cases with no cytogenetic clonal abnormalities, and 18 with clonal karyotypes or leukemia. We found that all aspirate smears had ≥10% atypical megakaryocytes, predominantly characterized by small forms with hypolobated and eccentric nuclei, and forms with high nuclear-to-cytoplasmic ratios. Core biopsies showed variable cellularity and variable numbers of megakaryocytes with similar features to those in the aspirates. Granulocytic and/or erythroid dysplasia (≥10% cells per lineage) were present infrequently. Megakaryocytes with separate nuclear lobes were increased in patients with myelodysplastic syndrome (MDS) and acute leukemia. Comparison to an immune thrombocytopenic purpura cohort confirms increased megakaryocytes with hypolobated eccentric nuclei in FPDMM patients. As such, patients with FPDMM often have atypical megakaryocytes with small hypolobated and eccentric nuclei even in the absence of clonal cytogenetic abnormalities; these findings are related to the underlying RUNX1 germline mutation and not diagnostic of MDS. Isolated megakaryocytic dysplasia in patients with unexplained thrombocytopenia should raise the possibility of an underlying germline RUNX1 mutation.

The Shwachman-Diamond Syndrome Registry: Hematologic Complications

The Shwachman-Diamond Syndrome Registry (SDSR) was established in December 2008 with the goal of understanding the natural history and biology of SDS to improve the lives of people with SDS. The SDSR has enrolled 220 patients with biallelic SBDS mutations or SDS-Like features. Longitudinal data has been collected for 176 patients with a median duration of follow-up of 10.7 (0.3-52.8) years. Biallelic SBDS mutations were noted in 117 patients, and biallelic DNAJC21 mutations in one patient. Sequencing of genetically undefined cases did not identify EFL1 or SRP54 mutations. Ongoing characterization of SBDS mutation-negative individuals has identified subgroups of clinically defined SDS individuals, as well as a more heterogenous subgroup with features of SDS but who do not meet classic diagnostic criteria. Clinical characteristics and outcomes of patients with biallelic SBDS mutations were examined. AML developed in 5 patients and MDS in 11 patients at a median age 37.9 years (range, 19.5-47.3) and 10.7 years (range, 1-45) respectively. No solid tumors were diagnosed. 21 individuals have undergone stem cell transplantation. Overall survival was 91% in the 10 years since registry establishment, with deaths mainly caused by myelodysplasia (MDS) (n=3) and acute myeloid leukemia (AML) (n=4). One individual with MDS died of hepatic failure unrelated to MDS. Hematologic parameters, trends over time, and clinical correlations were examined.. Cytopenias were almost universal (98.8%) and often intermittent, with neutropenia the most frequent in 98.8%, anemia in 16.5% and thrombocytopenia in 45.3%. Bone marrow evaluations were available in 98, with 88.2% demonstrating marrow hypoplasia. Notable, marrow hypoplasia was progressive, with average marrow cellularity of 74% in patients <1 year of age (n=13), 45% in marrows of children 1-19 years of age (n=277), and 38% in marrows of adults 19-43 years of age (n=38). Cases with discordance between marrow cellularity and cytopenias were noted, so a systematic analysis of the patterns of marrow cellularity and blood counts is ongoing. Marrow dysmorphologies were common and present in in 40.9%, 49.5%, and 28% of the erythroid, myeloid and megakaryocyte lineages respectively, highlighting the need for review from pathologists experienced in the baseline dysmorphologies common in SDS. Marrow cytogenetic data were available for 89 patients of whom 30 (33%) developed clonal abnormalities diagnosed at median age of 8.67 years (range, 0.3-38.9). The most common clonal abnormalities were iso(7q) (n=4) and del(20q) (n=13). Blood count patterns associated with these clonal abnormalities were variable. Notably, iso7q clones were transient while the majority of del20q clones were persistent. One patient with a history of an iso(7q) clone and one with a del(20q) clone progressed to MDS. There is a paucity of evidence to guide optimal surveillance strategies for leukemia predisposition syndromes. The SDSR revealed wide variation in clinical practice amongst local hematologists including: 1) no surveillance for well-appearing patients, 2) intermittent blood counts, or 3) bone marrow exams of variable frequency with variable testing of cytogenetics and FISH. Some patients were not followed by hematology because they looked well until they presented with AML. In one illustrative case, a teenage patient with a transient iso7q clone had improving hemoglobin, platelet counts, absolute neutrophil counts, and reduction in red cell macrocytosis over the year prior to diagnosis of MDS. Additional clinical and laboratory studies are underway to provide evidence-based guidelines and to develop more sensitive tests for optimal surveillance of patients with predisposition to myeloid malignancies. Disclosures Myers: Novartis: Membership on an entity's Board of Directors or advisory committees; Bellicum Pharmaceuticals: Membership on an entity's Board of Directors or advisory committees.

Unique Case of Myeloproliferative Neoplasm with Two Rare Clonal Abnormalities: Rare JAK2 Exon 12 Mutation and Rare e14a3 (b3a3) BCR/ABL Fusion Transcript

Myeloproliferative neoplasms (MPNs) are clonal disorders divided into Philadelphia (Ph) chromosome-positive chronic myeloid leukemia (CML) or Ph chromosome-negative MPNs. Co-occurrence of these disease entities is very rare and typically involves presence of common p190 or p210 BCR/ABL fusion transcript (responsible for CML) along with JAK2V617F mutation (most common driver mutation in Ph-negative MPNs). Because of the rarity of such cases, it is not clear if the outcomes are any different in these patients. In this article, we report a unique patient with polycythemia vera driven by a rare complex in-frame deletion-insertion mutation in JAK2 exon 12, and CML driven by uncommon p210 e14a3 (b3a3) BCR/ABL fusion transcript. We describe clinical and laboratory features, bone marrow pathology, treatment, and overall outcome.

Detectable clonal mosaicism in blood as a biomarker of cancer risk in Fanconi anemia

Key Points Fanconi anemia patients have exacerbated cytogenetic clonal mosaicism as detected by molecular karyotyping of blood DNA with SNP assays. Bone marrow clonal abnormalities can be detected in blood DNA and used as biomarkers of cancer risk and poor prognosis.

The North American Shwachman-Diamond Syndrome Registry: Genetically Undefined Shwachman-Diamond Syndrome

Shwachman-Diamond syndrome (SDS) is an inherited marrow failure syndrome associated with exocrine pancreatic dysfunction and an increased risk of myelodysplasia and leukemia. The majority of individuals with SDS carry biallelic SBDS gene mutations, however a subset of patients remain genetically undefined. The objective of this study was to compare the clinical characteristics of patients with and without SBDS mutations. To address these questions, we conducted a retrospective study of patients enrolled on the North American Shwachman-Diamond Syndrome Registry (SDSR). Clinical data from the SDSR were available for 55 individuals with biallelic SBDS mutations and 16 individuals who fulfilled clinical diagnostic criteria for SDS but lacked biallelic mutations in the SBDS gene. Study subject ages for SBDS mutation positive and negative cohorts span 2-52.4 and 2.8-21.4 years with median ages of 12.4 and 10.9 years respectively. Cytopenias were present for both SBDS mutation positive and negative cohorts, with neutropenia the most common event in 94% and 81% respectively. Bone marrow hypocellularity was reported in 91% of those with SBDS mutations and 69% of those without. Marrow dysplasia was reported in 65% of those with SBDS mutations and none of those without. Clonal abnormalities were present in 44% and 25% of those with and without SBDS mutations with median age of initial appearance at 9 years (0.8-45.1) and 7 years (1.2-14) respectively. Abnormalities included del7q and del20q in both groups as well as iso7q, trisomy 8 and others in the SBDS mutation positive group. Clonal abnormalities were all transient in the SBDS mutation negative cohort. One SBDS mutation positive individual developed AML. None of the SBDS mutation negative individuals developed malignancy or progressed to require HSCT thus far. Pancreatic dysfunction determined by low serum trypsinogen or pancreatic isoamylase was similar in both cohorts 79% vs 80%. However, only 27% (15/55) of SBDS mutation positive individuals reported requiring enzyme therapy with 33% (18/55) documenting failure to thrive, in contrast to 75% (12/16) of SBDS mutation negative individuals with 73% (11/15) having failure to thrive. A broad spectrum of congenital anomalies were reported in 55% and 56% of SBDS mutation positive and negative individuals respectively, with skeletal anomalies being the most common in both groups. Medical comorbidities commonly reported in both groups included eczema and endocrinopathies. Elevated liver transaminases were seen in 27% of SBDS mutation positive individuals but this was not seen in the SBDS mutation negative cohort. Conclusion: Patients with genetically undefined (SBDS mutation negative) SDS share clinical characteristics with SBDS mutation positive patients; however, the risk of leukemia in the genetically undefined patients remains unclear due to low patient numbers with short follow-up. Further studies of this young cohort are required to inform medical management and to advance our understanding of genetic etiology, mechanism, disease pathophysiology and treatment of these marrow failure disorders. Disclosures Dale: Amgen: Consultancy, Honoraria, Research Funding, Speakers Bureau.

An Interphase Chromosome Profiling Assay to Determine the Need for CD 138 Enrichment in the Genetic Workup of Multiple Myeloma

Plasma cell neoplasm, a B-cell malignancy is very common in elderly population and is currently incurable despite multiple treatment strategies. Genetic characterization, especially karyotype plays an important role in the diagnosis, prognosis as well as in the follow-up during treatment. In general, plasma cells are non-dividing and don't cooperate in tissue culture and as a result, over 90% of all standard cytogenetic studies end up having a "normal" karyotype. FISH testing using several probes has proven very useful in detecting the clonal abnormalities. It has been suggested and some laboratories do use CD138 antibodies to enrich the plasma cells in an effort to increase the detection rate of clonal abnormalities. However this additional step adds cost to the overall testing and the efficacy of this enrichment and the clinical utility is somewhat controversial. Many institutions don't enrich the plasma cells and still can detect the clonal abnormalities using FISH probes. It would be of interest if the need for enrichment is clarified and if the results from un-enriched studies are comparable to those of enriched, then the cost savings will be obvious. FISH testing, while extremely useful in increasing the detection of clonal abnormalities on the "normal" cytogenetic samples, has limitations in the sense that it can only detect the common changes targeted in the panels. Approximately 25% of all abnormal cases do have complex karyotypes harboring changes both numerical as well as structural that are beyond the scope of detection utilizing the current FISH panel of probes. These additional clonal changes have prognostic significance and it is well established that the greater the complexity of the karyotype, the worse is the prognosis. Therefore, it is imperative, from a clinical management standpoint that the testing laboratories use technologies that will detect all chromosomal abnormalities given the dismal culture success rate of traditional cytogenetic methods in detecting the abnormal clones. We have recently developed and validated a novel technology termed "Interphase Chromosome Profiling" (ICP) (Cytogenet Genome Res 2014;142:226, Abstract #22) which detects all chromosome abnormalities including the characterization of marker chromosomes and material of unknown origin i.e., add, in karyotypes. We utilized this technology on 10 unenriched samples from patients clinically suspected of multiple myeloma/plasma cell neoplasm. Each case had the traditional karyotype and FISH studies, in addition to ICP. Seven of the ten had a normal result with cytogenetics and FISH. ICP also produced a normal result in these cases. Three cases had an abnormal result by Cytogenetics and FISH. One of them had only one cell with abnormalities in the cytogenetic study. All three had complex karyotypes harboring the classic numerical abnormalities characteristic of multiple myeloma such as trisomy for chromosomes 3, 5, 7, 9, 11 etc. as well as multiple structural abnormalities including marker chromosomes and extra material of unknown origin (add). FISH failed to identify many of these structural changes which is an inherent limitation of the current design of panel of probes in clinical use. ICP on the other hand, detected not only all the abnormalities identified by both cytogenetics and FISH, but clarified and/or characterized the marker chromosomes and "add"s in these complex karyotypes. Interestingly, ICP identified a NOVEL duplication of the long arm of chromosome X, dup(X)(q21.3qter) in two of the three abnormal cases. Review of the literature indicates that this duplication on X chromosome is found in 20% of cases and harbors Cancer/Testis Antigens (CTAs) belonging to the MAGE family (CTA-X-MAGE) (Clin Dev Immunol. 2012;2012:257695. doi: 10.1155/2012/257695. Epub 2012 Mar 11) and is a potential target for novel immunotherapies. Yet classical cytogenetic approaches including FISH on enriched or unenriched samples will fail to identify this very important and common abnormality for which there is a potential therapy. Our results strongly indicate that ICP is very sensitive technique and can identify all chromosome abnormalities in interphase nuclei regardless of enrichment procedures for samples from multiple myeloma patients. Disclosures No relevant conflicts of interest to declare.